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Existing Structure Shoring

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Shoring existing structures can be a tricky business and the older the building, the trickier it can become.  Many older structures do not have drawings of the existing construction and if they do, they are not always reliable.  Many buildings go through generations of remodel with additions, renovations and improvisations that are not always documented properly.  Without proper documentation, it is sometimes difficult to determine the load bearing members in an existing building and this makes it difficult to shore.  If you can’t figure out where the loads are concentrated, you can’t figure out how to safely and economically support anything.

When undertaking the task of existing structure shoring you should consider consulting an engineer – and I don’t just say that because I happen to be an engineer!  The peace of mind that you get from entrusting this work to an engineer far outweighs the risk of liability if something goes wrong during the shoring operation. 

Things that your engineer will need to know before starting a shoring plan include the type of work being performed, the boundaries of work, distance to any excavation, dimensions of the building and location of load bearing members.  Other pertinent information includes the dead load of the supported area and any anticipated live loads – for example, will an office building remain occupied or is your customer trying to keep the parking garage operational during construction?  Depending on the scope of the job, snow and wind loads may also need to be taken into account.  Be certain to consider any special circumstances like required access openings in the shoring plan and work sequencing that would affect the standing shores.  Drawings, schematics and photographs can be provided to convey most of this information but, in some cases, it is easier and most cost effective for the person designing the shoring plan to visit the site.

If an existing structure is improperly shored, there is danger of damaging the building or of a collapse.  Providing as much accurate information as possible to your shoring designer will help to minimize risk and ensure the most accurate and economical design.  Don’t take chances, if in doubt get a professional engineer involved and maximize your chances of shoring success!

Fall Protection – The Full Package

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It has been said that the best solution for fall protection is to not fall, but as falls account for several deaths on construction sites, it turns out this plan doesn’t work out and will make OSHA very grumpy. This topic may be stale news to the salty veterans who have been around the block a time or two but I would be willing to bet that there are very few who consider all aspects of a fall protection every time they don their harness.

Whether you are the engineer designing the plan or the contractor whose life relies on the plan, there are several aspects of fall protection that need to be considered. The most familiar components of fall protection are the personal fall arrest system and the anchor which the system is attached to. Most anyone who has needed to utilize fall protection in their line of work knows that OSHA requires you to use a personal fall arrest system and be connected to a suitable anchor which is capable of supporting 5,000 pounds or be designed by a qualified person. In addition a fall protection user must consider the anchor location in relation to the work area, the fall distance and a rescue plan which are just as important and easier to overlook.

After determining the personal fall arrest system and a suitable anchor, next, consider the work area in relation to the fall protection anchor: It is always a good practice to keep the fall protection system as close to 90 degrees to the edge of the fall hazard as possible. This will limit the amount of swing in the event of a fall reducing the risk of the worker swinging into an object below.

Next, consider the fall distance to prevent a worker from hitting a lower level or an obstruction below as they fall. This aspect of fall protection has the highest variability and can change with each setup. The fall distance can be as little as a few feet if using a self-retracting lifeline attached to a rigid anchor to upwards of 20 feet with some horizontal lifeline applications.

Finally, any fall protection plan is pointless without a way to rescue the poor soul hanging from the system. The fact of the matter is that the fall is not the only way to cause injury and/or death. The sustained mobility of being suspended and the potential for the harness to restrict blood flow can cause serious issues if the worker is not rescued within a reasonable amount of time.

A well designed and implemented fall protection plan must consider all of these aspects. Fall protection may or may not be your bread and butter, however when you need it, considering only some of the aspects could turn into a very bad day. All good ideas start with a plan but without the follow through you’re just a guy hanging there hoping on a dream.

FAQ’s ABOUT FALLS

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A lot has been said about falls and fall protection. The U.S. Federal Occupational Safety & Health Administration, OSHA, has emphasized fall hazard awareness and increased enforcement of the fall protection regulations for years in the hope that deaths and major injuries due to falls in the workplace can be reduced. Manufacturers and suppliers are complementing the OSHA emphasis by offering a plethora of products that can be used to keep employees from falling. Or, more accurately, to keep employees from falling from heights to levels below in such a manner that they get injured or killed.

Due to the complexity of fall protection, it is not a simple procedure to provide personal fall protection equipment in such a way that it will protect an employee in all situations all the time. Confusing the matter is the inaccurate information, conflicting codes and interests, and a whole bunch of misconceptions about fall protection. Here are a few of the more frequently asked questions (FAQS)

What’s a personal fall arrest system? A personal fall arrest system (PFAS) consists of a full body harness, a shock absorbing lanyard or self-retracting lanyard, a vertical lifeline or horizontal lifeline, and an anchor. Alternatively, the lanyard can be attached directly to an anchor, eliminating the lifeline.

Is it true that I can use either a guardrail system or personal fall arrest system when working on a supported scaffold such as a frame or systems scaffold? That is true although the guardrail will be much more effective unless you are using the fall arrest system for fall restraint.

What is fall restraint? Fall restraint is using a personal fall arrest system to keep you from going off the edge of an exposed platform edge. It’s like hooking up the employee to a leash.

Why is a guardrail system more effective than a PFAS? A guardrail system keeps you on the platform or floor while a PFAS catches you after you have decided to leave the platform or floor.

I went bungee jumping once and found it to be exhilarating. Does one get the same thrill from falling off a floor while wearing a PFAS? I don’t know—I haven’t done either one although I want to jump off a bridge attached to a rubber band—sounds like fun. Falling from heights utilizing a PFAS, on the other hand is a whole different experience. While it is often perceived that no injury will occur due to a fall, the truth is quite the opposite. While there are those who experience no injury, typical injuries include severe bruising and intestinal damage. Frankly, the only thing worse than falling while wearing a PFAS is falling without a PFAS.

That doesn’t make sense: people use PFAS daily and I don’t hear of any injuries. What gives? The fact of the matter is that employees utilize/wear PFAS but very, very few actually use it. In other words, although employees wear harnesses and are attached to anchors, they rarely actually use the harness because they don’t fall from heights. Consequently, since they don’t fall, they don’t get hurt.

I have been told that my PFAS anchor has to hold 5,000 pounds unless it is designed by a qualified person, that is someone who knows how to design the anchor and system. Is this true?
Yes it is. The OSHA regulations and other codes require that the anchor you use has to be “capable of supporting at least 5,000 pounds per employee attached, or shall be designed, installed and used as part of a complete PFAS which maintains a safety factor of at least two and under the supervision of a qualified person.” [29 CFR 1926.502(d)(15)]

Are you telling me that before I attach my lifeline or lanyard to an anchor I must have someone determine it can hold 5,000 pounds? Yes.

Come on, no one does that. Everyone eyeballs the chosen anchor and estimates its strong enough. You mean I cannot do that? That is correct: OSHA says you cannot do that.

But it works; I mean that is what everyone does so isn’t it okay? It works because you don’t fall and therefore you never actually use the anchor! Just because you hook off to something that you call an anchor does not an anchor make. In other words, just because it looks good doesn’t necessarily mean it’s going to work. While not recommended, you must jump off the floor to see if your anchor will work.

Why does everyone get away with guessing as to the strength of the anchor? That’s easy; the regulation isn’t enforced. Besides, all the safety folks are happy if the guy is “tied off.” Luckily we don’t have too many employees jumping or falling off floors.

Isn’t tying off the same as utilizing PFAS? No way. You can tie off to anything, including yourself. Properly utilizing a PFAS means that you have selected an anchor that will support 5,000 pounds or you have tied off to an anchor designed by a qualified person in compliance with the mandatory OSHA regulations.

And what are those mandatory regulations? Here are a few: Limit the freefall to 6 feet; stop within 3.5 feet, (known as the deceleration distance); limit the force on the body to 1,800 pounds; and the most important, don’t hit the surface below.

That sounds complicated; is it? Yes, it can get very complicated to design a system that provides 100% fall protection and be in compliance with all of the applicable codes and OSHA regulations. Fortunately, the fall protection equipment manufacturers have done an incredible job of consistently developing new products that can be used to assist employers in protecting employees from fall hazards. It is amazing the changes that have occurred since I first got into the business many years ago. Unfortunately, too many employees lack the training to use the equipment properly. Fortunately, very few employees ever get the opportunity to actually use their PFAS!

How do I obtain the training to utilize and maybe use my PFAS correctly? There are numerous seminars that offer fall protection training. However, I suggest first contacting the manufacturer of your equipment since it should know its products. To learn about the applicable regulations, select a seminar that fits your needs, such as user, inspector or competent person. And finally, verify that the instructor is qualified to teach the seminar.

The ABCs of an Efficient Temporary Wall Bracing Plan

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A common concern for many of our clients is to improve the schedule of a job in order to increase revenue and profit. One of the most common ways for a project to gain time in a schedule is to install temporary wall bracing, typically using tilt-up style metal braces. When trying to design the most efficient temporary wall bracing plan, one might want to consider what I like to call the “ABC’s”:

A. Angle: brace capacities are given as an axial load.  After calculating the required horizontal bracing force, the designer must consider how the angle of the brace is going to transfer that horizontal load into an axial load.  This can drastically affect your brace spacing if your brace angle is 60 degrees versus 45 degrees.

B. Bottom: this is typically the main complication of a bracing plan.  The temporary brace resists the overturning of a wall near the top, but there is still the total horizontal load that needs to be resolved at the bottom.  For example, assume that the average load against a 12’ high wall is 5,000 lbs, and it is applied at 1/3 the height (this scenario is similar to backfilling a wall).  The overturning of that backfill is (5,000 lbs) X (12 ft) x (1/3) = 20,000 ft*lbs.  If the brace is installed at 10’, then the required horizontal capacity is (20,000 ft*lbs) / (10 ft) = 2,000 lbs.  However, if the original load against the wall is 5,000 lbs and the brace is only resisting 2,000 lbs, then the bottom of the wall still needs to resist 3,000 lbs.  Typically this is accomplished by installing the slab on grade.  If the slab on grade is not installed, then the designer must analyze the wall itself to resist the load or specify an additional permanent support.  If the wall itself is not sufficient, then it is typically in the best interest of the contractor to install the slab on grade.

C. Connection: connections will need to support shear loads vertically on the wall, horizontally on the slab, and vertically on the slab.  There may be limitations in the existing structure due to substrate thickness, edge/spacing distances, and ground bearing capacity.

By keeping these guidelines in mind, designers maximize the efficiency of bracing for the contractor and the project.

Seismic Retrofit of Existing Buildings

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The process of evaluating and designing the retrofit of existing buildings differs from the conventional structural design of new buildings. The current state-of-the-art analysis and design approach for the seismic evaluation of existing buildings is founded on a performance-based philosophy. There are two parts to a performance-based analysis and design.

First, there is the establishment of a performance objective. This answers the question for the designer and the owner, “What degree of damage to the building am I willing to tolerate in the event of an earthquake?” It is not economically feasible to design all buildings to a performance objective that limits all damage or allows the building to remain fully operational and allow immediate occupancy following an earthquake. Therefore, performance objectives exist that allow a certain degree of damage to occur while still protecting life safety and preventing building collapse.

Second, there is the establishment of the seismic demand used in the analysis of the building. Statistical analysis is used to determine the probability of the maximum considered earthquake (MCE) occurring at the building site at any given time. The MCE demand level varies based on the time frame considered and the probability that there will be ground motion at the site that exceeds the MCE (i.e. 5% probability of exceedance in 50 years). Together with these two variables the mean return period of an earthquake can be established (i.e. it can be expected that an earthquake of ‘X’ magnitude, or the MCE, will occur approximately at least every 975 years).

There are various performance objectives and seismic demand levels that may be considered. Any given combination of performance objective and seismic demand level will result in a varied stringency of analysis and design. Combining a strict performance objective (i.e. operational post-earthquake) with an earthquake of relatively long return period (2500 years) will likely result in a robust, yet potentially expensive, design.

In conventional structural analysis and design, the seismic demand used for the design of the seismic force resisting system is reduced by a system-wide Response Modification Factor, R. This coefficient is established based on the ductility of the lateral system selected for design. The R-Factor is intended to act as a representation of the ability of the lateral system to dissipate energy as it flexes, bends, and undergoes inelastic deformation under seismic load.

In the evaluation of existing buildings, the concept of reducing the demand to account for ductility in a system is captured by using component specific m-factors. Rather than reducing the seismic demand, m-factors are applied to scale up the strength or capacity of individual structural elements that experience ductile or “Deformation Controlled” failure. These m-factors vary by component and allow the design professional to apply a uniform seismic demand to the system while modifying the strength of each individual element of the system according to its ductility. This philosophy is ideal for seismic retrofits that require the introduction of an entirely new lateral system or the strengthening of only a few discrete components.

Bridge Overhang Brackets

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The proper design of bridge overhang brackets and related falsework is critical. Failure to properly design this falsework can result in partial collapse of the formwork/falsework, damage to the bridge structure and damage to equipment.

Typical bridge construction requires the use of falsework to support workers, the outer edge of the concrete bridge deck, deck screed and sometimes the weight of the concrete barrier.

Falsework is typically anchored to bridge girders by either cast in place steel anchors or by using a cast in place sleeve that allows the use of a threaded rod or coil rod. These anchors can then be fastened to the overhang bracket itself.

Bridge Overhang BracketsCast in place anchors for bridge formwork is available by many suppliers. Some critical things to consider is where the anchor is placed. In box beams for instance, the thickness of the concrete along the top of the box beam may limit the capacity of the anchor. If the capacity of the anchor is limited, then the spacing of the brackets will need to be reduced, resulting in increased costs of equipment and labor. For Bulb Tee beams care also needs to be used when deciding where to place either cast in place anchors or tubular inserts. If cast in place anchors are used, they are typically placed on the edge of the top flange. If the top flange is too thin, then the flange of the girder may be the weak link in the system. Where tubular inserts are used the strength of the girder is less of a concern. When using tubular inserts, a special bracket (typically a steel angle) is required to allow the nuts for the inserted rod to bear properly and prevent bending of the rod.

Supports between the overhang brackets can be made of almost any material. Typically lumber 4×4’s or aluminum beams are used. Additional supports are required under the screed form and may be much larger than the typical supports. The support beams under the concrete deck typically have a tighter spacing than for the walkway.

Where very large screed equipment is used, the equipment typically has a set of multiple wheels. Analysis of the supporting beams for the screed load is a complicated task. Analysis of the multiple screed wheels on a multiple span beam at multiple locations along the beam is required to determine the maximum shear, bending and reaction forces.

On occasion, high winds can cause major damage to the falsework. Wind uplift forces have in the past resulted in the falsework being lifted up and over the edge of the bridge resulting in construction delays and equipment damage. Entire girders may need to be replaced if cast in place anchors were used. To prevent this type of problem multiple methods for holding down the falsework can be used. Brackets can be held down with sandbags, tied with wire to concrete blocks/road barriers or can be anchored to the girders themselves (if allowed).

Plank Criteria

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There are two criteria that predict the safety of a scaffold platform.  One of the criteria involves the engineering properties of the scaffold unit.  The other criterion addresses the correct installation of the platform.  Correct installation includes proper support, correct positioning to limit spaces between platform units, and the minimum width of the platform.

The Federal Occupational Safety and Health Administration, OSHA, and other agencies, set forth the minimum standards for the installation and use of platform units.  For example, regulations address the minimum and maximum overhang of platform units, the allowable deflection, the space between units, and the distance from the edge of the platform to the work surface and the guardrail system.  These regulations are in the subsection on platforms, 29CFR1926.451(b), and are quite specific.  The regulations address all platforms, including solid sawn wood plank, laminated veneer lumber (lvl), metal fabricated decks, and platforms constructed of structural members and sheathing such as plywood.  These specific regulations ensure that the platform you construct will stay on the scaffold, will be large enough so you won’t fall off the platform, and won’t have any openings that you may fall through.

Engineering properties also predict the safety of the platform.  For manufactured platforms, such as aluminum decks and laminated veneer lumber, the manufacturer indicates the capacity of the product.  For solid sawn plank, determining the capacity is not as straightforward due to varying factors.  These factors include the dimensions of the plank, the specie of tree, what part of the tree is being used, and if the wood has any damage.  How in the world do you determine if the plank is strong enough?  Fortunately, you have help!  Qualified engineers can determine the strength of the plank you are using if the dimensions, the specie of tree, and the quality of the wood are known.  The engineer will also need to know the span of the plank, that is, the distance between supports.  While you can give the engineer the dimensions and span of the plank, the type and quality of the wood is another story.  Unless you cut the tree down yourself, you probably won’t be able to tell if the wood is pine or poplar.  And unless you have learned how to grade lumber, you won’t know if the wood is any good.

How, then, is the grade of the wood determined?  Qualified, trained lumber graders are one method used by lumber mills to determine the strength of wood.  These individuals are trained to determine the various strengths of wood that will come from a tree.  Factors used to determine strength include such things as density (how many rings per inch), the straightness of the grain, and the frequency of knots.  Straighter grain, higher density, and fewer knots will result in a strong piece of wood.  On the other hand, frequent knots and low density will result in a low strength piece of wood.

The engineer relies on the ability of the grader to do his or her job correctly.  The engineer also relies on the accuracy of the stamp to determine precise information for you to use.  The bottom line here is that the information in the grade stamp dictates the accuracy of the engineer’s calculations.  Of course, this information will only be accurate if the plank you use has been graded by a qualified grader, using recognized standards.  If the wood is not as good as the grade stamp indicates disaster will surely follow.

For typical situations, it is recommended that only Scaffold Grade plank be used since this will enhance safety on your scaffold project.  Scaffold Grade plank is a very specific grade of lumber that has a very high strength compared to other commonly found lumber on a construction project.  However, if you choose to use a plank other than scaffold grade, it must be engineered for proper use.  This is the only way you will be safe and in compliance with the regulations.

Do not take chances with solid sawn wood plank.  A grade stamp from a recognized grading agency is your guarantee of accuracy.  High strength lumber is not cheap.  Neither is a worker’s life.  If the board breaks, there is no back-up.

Here Are Some Scaffolding Answers!

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Here are answers to frequently asked (and some not so frequently asked) questions regarding scaffolding and related subjects:

Q: Do scaffold users have to have scaffold training.

A: Of course they do—why wouldn’t they? They need to be trained in fall protection, access, falling object protection, proper use, the scaffold load capacity, electrical hazards and proper handling of materials on the scaffold. [OSHA 29 CFR 1926.454(a)]

Q: Does a ladder have to stick 3 feet above the scaffold platform?

A: Only if it is a portable ladder. Purpose built attachable scaffold ladders do not although it is a good idea unless you have hand holds (such as the scaffolding) available.

Q: Does a portable ladder have to be tied at the top?

A: Not if it is sticking 3 feet above the platform.

Q: A supported scaffold ladder is straight up and down like a fixed ladder and clamped to the scaffold. Doesn’t that make it a fixed ladder?

A: Nope. It’s an attachable ladder purpose built for scaffolds. OSHA 29 CFR 1926, Subpart X – Stairways and Ladders does not apply. (Read the Subpart X Scope and Application)

Q: Do I have to always use scaffold grade plank on my scaffold?

A: Not if your scaffold has to comply with the Construction Industry OSHA standards. If you have to comply with the General Industry or Maritime standards, then the plank must be scaffold grade. Of course the SAIA recommends that you always use scaffold grade plank or equivalent.

Q: What’s a high wind?

A: That’s subjective. If you get blown off the scaffold, that is a high wind. It is up to the Competent Person to determine what a high wind is. I would take jobsite conditions and the work activity into consideration when determining if it is time to vacate the scaffold. 20 – 25 mph is a popular maximum wind speed for supported scaffolds although I have been on scaffolds in 50 mph breezes. [You don’t get any work done because you’re spending all your time hanging on but you get bragging rights.] The SAIA Code of Safe Practices for Suspended Scaffolds recommends 20 mph for single point and 25 mph for two point suspended scaffolds.

Q: Is a “Self-Propelled Elevating Work Platform (aka scissors lift) an aerial lift or a Mobile Scaffold?

A: According to an OSHA Letter of Interpretation (LOI), OSHA thinks it’s a supported scaffold, similar to a frame scaffold. The industry knows it is an aerial platform because the consensus standards for it are in the ANSI A92 family of standards, not in the ANSI A10.8 standard which addresses the typical frame, systems, tube & coupler, and other like scaffolds.

Q: Are the OSHA scaffold standards instructions on how to use scaffolds?

A: Heck no; they are minimum requirements for safety, minimum expectations. In fact, you have to be trained in scaffolding before you can understand the regulations. Reading the standards does not a Competent/Qualified Person make!

Q: Why do I have to have a guardrail on a suspended scaffold if I am wearing personal fall arrest equipment?

A: We don’t want you to fall off the platform since catching you isn’t fun.

Q: Does that mean that when I am on a single or two point suspended scaffold I have to not only utilize a personal fall protection system but I have to be behind the guardrail system on the platform.

A: Duh—yeah.

Q: What about a multi-point suspended scaffold?

A: It depends on the scaffold. If the deck has many suspension points and the deck is very rigid, personal fall protection may not be necessary. On the other hand, if the deck is flexible, failure of one line can dump you off the platform. Ask the qualified designer what is required for fall protection. If nobody knows, use both a guardrail and personal fall protection. I would also recommend looking for a new job if nobody knows what the fall protection requirements are!

Q: If I stand on a plastic five gallon bucket, is it a scaffold?

A: You bet it is. A scaffold is any temporary elevated platform and its supporting structure used to support workers or materials or both. Assuming you turned the bucket over before you stood on it, the bottom of the bucket is your platform and the sides of the bucket are the supporting structure. I cannot tell you what the handle is.

Q: Does that mean that if I stand on a table I have to comply with the OSHA scaffold standards?

A: Why not? You’re using the table as a scaffold.

Q: Do I have to comply with the OSHA standards or do they only apply to my employer?

A: Nice try. The OSH Act of 1970 explicitly states that both the employer and the employee have to comply with the standards. [This is known as the “General Duty Clause” of the act.]

Q: What else does the General Duty Clause say?

A: It requires that the employer “shall furnish to each of his/her employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his/her employees.” This is also known as “Section 5(a)(1).”

Q: Do the OSHA standards cover all workplaces?

A: No. The federal OSHA standards do not cover state and local government employees; they apply only to the private sector.

Q: Do all 50 of the United States enforce the federal OSHA standards?

A: No. 21 states and 1 US territory have state plans that cover both private and state and local government workplaces. 5 states and 1 US territory cover state and local government workers only. Most states use the federal standards. Certain states have added to or revised the federal standards for use in their states. California’s OSHA scaffold standards are completely different from the federal standards.

Q: Why do states change the federal standards?

A: I have no idea—a broken arm in the Virgin Islands is the same as a broken arm in Alaska.

Q: I am on a project where the Army Corps of Engineers had authority. Do they use the federal standards?

A: Yes and no. They have to comply with federal OSHA but they also have standards that are referred to as EM-385 that are part of the contract. And yes, the EM 385 scaffold standards are much more stringent and more confusing.

Q: I was told that 19” is the maximum first step for accessing a scaffold. Is that correct?

A: Nope. It is 24 inches. 19 inches is the maximum first step for everything except scaffolds.

Q: Where do you find all this information?

A: I make it up, just like a lot of people on the jobsite. JUST KIDDING! The OSHA standards can be found at www.oshsa.gov; the Codes of Safe Practices can be found at www.saiaonline.org and www.ssfi.org. DH Glabe & Associate also keeps a wide variety of info on its’ resources page www.dhglabe.com/free-resources. The ANSI A92 standards can be purchased from the SAIA. Other standards can be purchased from ANSI or the American Society of Safety Engineers. Training on how to use scaffolds can be obtained from the SAIA and other sources. Be sure to investigate the quality of the training before purchasing—there are a lot of supposed experts who do not have the credentials.

Scaffolds Falling Down

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Recently there has been a rash of supported scaffold collapses. That’s not good for either the scaffold user or the industry’s reputation. What possibly could be going on? Is it an act of terrorism? Is it due to the fickle finger of fate? Or perhaps, is it just one of those things that cannot be avoided? After all, it is a scaffold.

And therein lies the issue—too few people take scaffolding seriously. Oh sure, OSHA diligently scrutinizes scaffolding on a regular basis, reminding errant erectors and users of their indiscretions and awarding them with citations. Organizations promulgate standards while manufacturers write recommendations and trainers train trainees. And scaffolds still fall down. Something is amiss; there is a piece (or pieces) of the jigsaw puzzle missing. What is the missing link, that missing magic pill that will make the world right? Unfortunately, there is a no magic pill, no easy solution to a correctly designed, constructed and used scaffold. A scaffold requires work, and oftentimes hard work.

It requires an employer to provide training for his or her employees. It requires manufacturers to design and manufacture a safe product. It requires suppliers to provide a safe product. It requires designers to design a scaffold that has the strength to support the anticipated loads and it requires the erectors to build it according to that design. Finally, it requires the user to use the scaffold correctly. Is that too much to ask? Apparently it is if the recent disasters are any indicator.

Correctly designed and erected scaffolds are incredibly strong, much stronger than a typical structure. And still, the scaffolds collapse. Adequately trained employees won’t abuse, misuse or alter a scaffold, but the scaffolds still collapse. What’s the secret to stopping this epidemic of failed scaffolds? It’s easy: Do your job. Here are a few factors that will influence a scaffold’s decision to collapse or not to collapse:

  1. Make sure you are using a legitimate product, one that has accurate load charts based on testing performed in compliance with the SSFI recommended testing procedure.
  2. Manufacturers, see #1. Just because your stuff looks like someone else’s stuff doesn’t mean you can use their test data.
  3. Purchasers, see #1 and #2. There is a reason prices vary; find out why before you buy that really cheap container load of frames.
  4. There is a limit on what a scaffold can hold and that limit is based on the scaffold being correctly designed and erected. Mess with the design or the erected scaffold and you’re courting disaster.
  5. Bad or no design: Supposed scaffold designer, just because you can put parts and pieces together doesn’t mean you are a designer. After all, a five year old can assemble tinker toys. Learn how to do it correctly, not just do it.
  6. Lack of adequate bracing: Do you know what the correct bracing pattern is? Do you know what the bracing does?
  7. Poor foundation: Just because there is a piece of wood under the leg doesn’t mean you have a good foundation. You have to know what’s holding up your scaffold. You can’t do that by guessing.
  8. A bad platform: Do you have any idea why a wood plank can support a load?
  9. Lack of adequate fall protection. This is a good one—talk about misinformation!
  10. Inadequate strength: You must know how much the scaffold can support so you don’t overload it.
  11. OSHA, see # 10 so you can correctly cite # 1926.451(a)(1).
  12. Inadequate or no training: Employer, do you know that you are to provide training for your employees? Keep in mind that the training requirement has been in existence since at least 1971.
  13. Lack of knowledge: Both employers and employees have to comply with the OSHA standards. How can you do that if you never read them?
  14. Not knowing what you are doing: Erectors are supposed to know how strong scaffolds are and what the scaffold will be used for after it is erected. I cannot remember one who could tell me when asked.
  15. More not knowing what you are doing: A person known as the “Competent Person” has to be able to identify the hazard and have the authority to eliminate it. How can you eliminate the hazard if you cannot identify it?
  16. Still more of not knowing: How do you know there is a hazard if you do not know what a properly designed and erected scaffold is?

The fact of the matter is that many supported scaffolds erected and used in North America do not comply with the critical obligatory safety standards. Sure, everybody knows that platforms are to have guardrails but that is but one aspect of a scaffold. Very few know the capacity of the scaffold, very few know which bracing is permissible and which isn’t; the list goes on. My experience shows me that the industry has too many unqualified people guided by other equally unqualified people.

OSHA compliance officers do not get sufficient training to do their jobs anywhere near the level of competency that they need. While we can, and should, blame an administration that does not provide high quality training at the necessary levels, it cannot be an excuse for a lack of knowledge. Frankly, knowing the regulations is a lot of work but if you are going to assume the authority you had better also take the responsibility and learn the subject matter at hand.

Too many people think that merely fitting the parts together is good design. Fit has nothing to do with proper design. If you are a designer, it is expected that you have learned how to design. Just because you are an engineer, or an erector, or a scaffold company owner, or a safety manager does not make you a designer. You must have the training, experience, knowledge and education to do the job. This includes knowing the principles of physics, the regulations, and the limits of the equipment. Remember, just because it fits together doesn’t mean a darn thing.

Simply stated, scaffolds do not collapse. A stack of metal, wood and plastic parts and pieces incorrectly called scaffolds collapses. Which one do you want? More importantly, what are you going to do now to make sure the next temporary structure you are involved with is a scaffold and not a stack of stuff?